Detection of T-cell receptor-gamma gene rearrangement in lymphoproliferative disorders by temperature gradient gel electrophoresis

Objective.-Polymerase chain reaction amplification of DNA for T-cell recept or (TCR) gene rearrangement analysis is helpful in the evaluation of T-cell lymphoproliferative disorders. Detection of polymerase chain reaction prod ucts is limited by the poor resolution of bands analyzed by agarose or poly acrylamide gel electrophoresis. To improve the detection of a clonal T-cell population, we used temperature gradient gel electrophoresis (TGGE) as an alternative method for analysis of TCR gene rearrangement. Design.-One hundred eighteen archival DNA samples were randomly selected ba sed on previous Southern blot analysis results. Samples included 58 T-cell neoplasms with positivity for TCR beta gene rearrangement, 22 cases of reac tive hyperplasia with germline pattern for both TCR beta and J(H), and 38 p atients with B-cell lymphoma. MOLT-16, a T-cell lymphoblastic cell line, wa s used for the sensitivity assay. Polymerase chain reaction was performed u sing CC-clamped multiplex primers to amplify the TCR gamma locus and was an alyzed by TGGE. The range of temperature gradients was empirically determin ed for optimal resolution of bands. Results.-The sensitivity of TGGE was 0.1% when DNA from the MOLT-16 cell li ne was serially diluted with DNA from reactive lymphoid tissue. Fifty-four (93%) of 58 T-cell neoplasms with TCR beta gene rearrangements showed rearr angement patterns by TCR gamma TGGE, and only 1 of 60 samples (reactive or B-cell lymphomas) showed evidence of gene rearrangement by TGGE. Patients w ith T-cell neoplasm and involvement of multiple sites showed an identical m igration pattern by TGGE analysis. Conclusion.-We demonstrate that TGGE is an effective method for analysis of TCR gene rearrangement in the evaluation of nodal and extranodal lymphoid lesions.